anyone know how to enable/disable this via command?
or where is this store in mirc.ini

This is a standard Windows command, not mIRC, so I don't know if it can be disabled.

options > others > keys >

but i want to enable/disable this via command

I can't find anything searching through my resources, so it's very possible that what you want doesn't exist.
Based on this, and presuming someone doesn't post information contrary to what I have, you may want to consider making a Feature Suggestion.